Electronic Service Guide (ESG) is one of important aspects in application layer technologies of mobile communications. A terminal user may use the ESG to view conveniently various service materials, to browse a video channel, a program schedule, a price table, to select and purchase an item in the price table, and to link to an external web page to browse related information, etc.
At present, there are two methods with respect to ESG, one is a broadcast ESG and the other is an interactive ESG. In the broadcast ESG, a terminal is initialized through a bootstrap session of the broadcast ESG, reads a list of ESG providers from ESG discovery information and displays it to the terminal user. After the terminal user selects an ESG provider, the terminal is tuned to a specific session in accordance with ESG access information in the ESG bootstrap session and receives ESG data of the ESG provider selected by the terminal user, as illustrated in FIG. 1.
In the interactive ESG in the prior art, a terminal user may submit an enquiry request and user profile, etc., to a server, and this may bring abundant ESG functions.
The interactive ESG may be implemented with a Web Service. The Web Service is a new branch of web page application programs, and it may provide summarily the functions over the Internet and an enterprise intranet by means of standard Internet protocols, e.g., the Hyper Text Transfer Protocol (HTTP) and the eXtensible Markup Language (XML). The Web Service may be regarded as component programming on a web page. The Web Service is an independent and modular application and it may be described, published, located and invoked over the Internet. The architecture of the Web Service includes three parts: a service provider, a service requester and a service registry. There are primarily three operations, i.e., Publish, Find and Bind, presented between the respective parts.
The Web Service per se is provided with a perfect discovery mechanism. The existing standard of Universal Description, Discovery and Integration (UDDI) defines a method for discovering and using a Web Service in the case of an unknown Web Service location. The UDDI may enable an application program to discover and contact a server providing a given Web Service. After an interactive channel is introduced between a terminal and a server, the terminal may submit an enquiry request to the UDDI server via the interactive channel and obtain Web Service invocation information of a specific ESG provider, and thereafter the terminal may invoke the specific Web Service according to the obtained information.
FIG. 2 is a flow chart of discovering an interactive ESG service in the prior art. This flow includes the following steps.
In step 201, a terminal submits an interactive ESG enquiry request to a UDDI server.
In step 202, the UDDI server processes the received interactive ESG enquiry request and obtains from its stored information the Web Service invocation information satisfying the interactive ESG enquiry request.
In step 203, the UDDI server returns to the terminal the Web Service invocation information of the interactive ESG.
In step 204, the terminal parses the received Web Service invocation information of the interactive ESG and determines a format to submit a data request to an interactive ESG provider.
In step 205, the terminal submits the data request in the determined format to the interactive ESG provider.
In step 206, the interactive ESG provider processes the data request of the terminal and obtains from its stored information the ESG data satisfying the request of the terminal.
In step 207, the interactive ESG provider returns to the terminal the ESG data complying with the request of the terminal.
This solution is disadvantageous in that bandwidth consumption is not stable and the load of the interactive channel will be increased in the case that a plurality of terminals requests concurrently the server in the interactive channel for discovering an interactive ESG service. In addition, since a plurality of terminals request concurrently the UDDI server for enquiring the interactive ESG, load of the UDDI server will be too heavy.
Further, different terminals have to download the same information respectively from the same interactive ESG provider to discover this interactive ESG provider, which may consequently lower the efficiency of using the interactive channel.
In the prior art, another technology to obtain Web Service invocation information is a Web Service inspection (WS-inspection) technology. The WS-inspection technology provides Web Service related information in a totally distributed mode. The WS-inspection technology integrates descriptions of different types of ESG services in a WS-inspection document, and when a terminal needs to discover an interactive ESG service, the terminal sends a request for obtaining Web Service invocation information directly to a service delivery point where the WS-inspection document is stored; and the service delivery point searches in its stored WS-inspection document according to the received enquiry request, and use an existing standard to return the Web Service invocation information to the terminal in accordance with a WS-inspection specification. The adoptable existing standard may be the Web Service Description Language (WSDL), etc., and thus the terminal may make direct use of the obtained Web Service invocation information without any modification. In the prior art, the XML format is used for the WS-inspection document.
In this method of obtaining Web Service invocation information through a WS-inspection, related information has to be downloaded from a known service delivery point address via an interactive channel, which may consequently increase the load of the interactive channel and lower the efficiency of using the interactive channel.
In summary, the solutions of discovering an interactive ESG in the prior art require interaction between a terminal and a server to obtain Web Service invocation information, which may result in an increased load of an interactive channel and a lowered efficiency of using the interactive channel.